At the Department of Computer Science, some of the undergraduate
courses have large student enrolments. This is especially
so for the lower level undergraduate courses. Lecturing to
a large class poses some challenges. Typically, there is limited
student interaction during each lecture. Consequently, how
to increase student participation during lectures in order
to facilitate teacher-student and student-student interaction
becomes an important issue.
In this short article, I will share my experience in a classroom
experiment conducted with the aim of increasing student participation.
The experiment took place during Semester 2 of Academic Year
2002/03. The class involved had more than 170 students, mostly
second-year undergraduates majoring in computer science. The
course covered introductory artificial intelligence.
Ingredients of the experiment
One way to increase student participation is for the teacher
to pose questions to the students. The hope is that students
will be forced to think and reason when faced with questions,
and that answering the questions gives them an opportunity
to interact with the teacher. However, this approach of posing
questions may not work well in practice. Lecturers and students
are all too familiar with the situation when a question posed
is met with deafening silence. Even after repeated prompting,
students are still too shy to volunteer to answer the question.
A better way to encourage students to speak up is needed.
In my experiment, after I posed the question, I first got
the students to discuss in groups of two (i.e. each student
discussed the question with his/her neighbour seated next
to him/her) for two minutes. This serves as an icebreaker,
since students are generally less inhibited when they engage
in small-group discussions. It also achieves the aim of increasing
student-to-student interaction during the lecture.
In order to challenge the students to engage in higher-order
thinking, a question that leads the students to relate different
parts of the course material and to ‘see the big picture’
is preferable, instead of a question that asks them to regurgitate
facts. In the experiment, the lecture topic was on machine
learning. The question I asked was: “Give an algorithm
to generate a good decision tree that maps an example to a
category, given a set of examples with assigned categories.”
At the point of posing this question, I had not touched
on any learning algorithms. However, earlier topics of the
course covered include search, representation and inference,
and planning. It was pointed out to the students before that
both inference and planning could be viewed as a search procedure.
Hence, a deep understanding of these previous topics would
enable a student to come up with an answer to the question
posed (i.e. a search algorithm that views learning as search).
Another aspect of increasing class participation is to engage
students in a discussion, instead of a one-way process of
posing a question and getting an answer back. This can be
brought about by asking sub-questions whose answers then lead
to more subsequent questions. In this way, the teacher can
provide hints and build upon the students’ partial answers,
and foster an interactive discussion in the process.
Outcome of the experiment
After warming up by discussing with their fellow students
first, the students were less inhibited in answering the question.
After some hints and prompting, one student was able to come
up with the correct answer. In the process, another student
even asked me to clarify a point.
Overall, the outcome of this experiment is that the students
did develop a deeper understanding of the connection between
the different parts of the course material. The students became
more active in class participation, not only in answering
the question, but also volunteering to ask a related clarification
question about the topic. The classroom atmosphere became
livelier as a result.
Pausing a lecture to get students to first discuss among
themselves a higher-order question takes up a bit more time.
However, this practice does break the monotony of lecture
and its occasional use brings benefits and increases student
participation in a large class.